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<html lang="en">
<head>
    <meta charset="UTF-8">
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    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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<body>
    
</body>
<script>
    function run(year){
        // return year % 4 == 0 && year % 100 != 0 || year % 100 ==0 ?  year + "年是闰年" :  year + "年不是闰年";
        
        year % 4 == 0 && year % 100 != 0 || year % 100 ==0 ? result = year + "年是闰年" : result = year + "年不是闰年";
        return result;
    }

    console.log(run(2000));
    document.write(run(2000));
    document.write(run(1999));
</script>
</html>